The present invention generally relates to various resonating configurations of filters employing a resonator device. More specifically, the present invention relates to various topologies for filters employing a resonator device.
Conventional strip-line filters known in the art employ planar resonator devices. FIG. 28 illustrates a top view of a known edge-coupled three resonator device 110 including a left resonator 111, a middle resonator 112, and a right resonator 113. The resonators 111-113 are aligned along their edges whereby the resonators 111 and 112 are edge-coupled, and the resonators 112 and 113 are edge-coupled. The edge-couplings of the resonators 111-113 establish a signal path from an input port 111a to an output port 113a as indicated by the arrow.
FIG. 29 illustrates a top view of a known two resonator device 120 employed within a parallel coupled line filter. A resonator 122 and a resonator 123 are approximately xcex/2 long. An input line 121 is edge-coupled to the resonator 122 by a gap GP1. The resonator 122 is edge-coupled to the resonator 123 by a gap GP2. Finally, the second resonator 123 is edge-coupled to an output line 124 by gap GP3. The aforementioned edge-couplings establish a signal path from the input line 121 to the output line 124 as indicated by the arrows.
One drawback of the resonator device 110 and the resonator device 120 is a failure to facilitate a fabrication of a filter employing the resonator device within a minimal substrate area. The present invention is an advancement of the prior art.
One form of the present invention is a filter comprising a plurality of metal layers and a plurality of dielectric layers arranged in a vertically stacked topology. A first metal layer includes a first resonator. A second metal layer includes a second resonator.
The filter can employ a third metal layer including an inner ground operable to broadside couple the first resonator and the second resonator.
The filter can employ a third metal layer including an inner ground having an aperture operable to couple a broadside surface of the first resonator and a broadside surface of the second resonator.
The filter can employ a pair of strip-line regions formed by the metal layers. An input port of the first resonator is isolated within a first strip-line region. An output port of the second resonator is isolated within a second strip-line region.
The foregoing forms and other forms as well as features and advantages of the present invention will become further apparent from the following detailed description of the presently preferred embodiments, read in conjunction with the accompanying drawings. The detailed description and drawings are merely illustrative of the present invention rather than limiting, the scope of the present invention being defined by the appended claims and equivalents thereof.